Plasma– a hot soup of atoms with free-moving electrons and ions– is the most plentiful kind of matter in the universe, found throughout our solar system in the sun and other planetary bodies. A new research study from University of Rochester scientists supplies experimental information about how radiation takes a trip through dense plasmas, which will help researchers to better understand planetary science and fusion energy.
First-of-its-kind speculative evidence contradicts standard theories about the emission and absorption of radiation by plasmas.
While liquids, gases, and solids are familiar states of matter, there is a 4th state called plasmas which is the most common type of matter in the universe. It can be discovered in the sun and other heavenly bodies in our planetary system. Dense plasma, which is a hot mix of atoms with free-moving electrons and ions, just occurs under very high pressure and temperature level conditions, making it challenging for researchers to completely understand this state of matter.
Research in high-energy-density physics (HEDP), which investigates how atoms act under extreme pressure conditions, can offer valuable insights into fields such as planetary science, astrophysics, and combination energy.
One essential concern in the field of HEDP is how plasmas soak up or release radiation. Existing designs depicting radiation transportation in thick plasmas are heavily based on theory rather than experimental proof.
In a brand-new paper published in the journal Nature Communications, scientists at the University of Rochester Laboratory for Laser Energetics (LLE) used LLEs OMEGA laser to study how radiation travels through thick plasma. The research, led by Suxing Hu, a recognized researcher and group leader of the High-Energy-Density Physics Theory Group at the LLE and an associate teacher of mechanical engineering, and Philip Nilson, a senior scientist in the LLEs Laser-Plasma Interaction group, supplies first-of-its-kind experimental information about the habits of atoms at severe conditions. The data will be used to enhance plasma designs, which allow researchers to better understand the evolution of stars and might aid in the realization of regulated nuclear fusion as an alternative energy source.
” Experiments utilizing laser-driven implosions on OMEGA have actually developed severe matter at pressures numerous billion times the climatic pressure at Earths surface for us to probe how particles and atoms act at such extreme conditions,” Hu says. “These conditions correspond to the conditions inside the so-called envelope of white dwarf stars along with inertial combination targets.”
Using x-ray spectroscopy
The researchers used x-ray spectroscopy to measure how radiation is transferred through plasmas. X-ray spectroscopy involves aiming a beam of radiation in the kind of x-rays at a plasma made of atoms– in this case, copper atoms– under extreme pressure and heat. The researchers used the OMEGA laser both to produce the plasma and to develop the x-rays focused on the plasma.
When the plasma is bombarded with x-rays, the electrons in the atoms “dive” from one energy level to another by either producing or absorbing photons of light. A detector measures these modifications, revealing the physical processes that are occurring inside the plasma, comparable to taking an x-ray diagnostic of a broken bone.
A break from conventional theory
The scientists experimental measurements indicate that, when radiation takes a trip through a thick plasma, the changes in atomic energy levels do not follow traditional quantum mechanics theories often utilized in plasma physics designs– so-called “continuum-lowering” models. The scientists instead discovered that the measurements they observed in their experiments can be finest described using a self-consistent technique based on density-functional theory (DFT). DFT offers a quantum mechanical description of the bonds between atoms and particles in complex systems. The DFT technique was first described in the 1960s and was the topic of the 1998 Nobel Prize in Chemistry.
” This work reveals essential steps for rewriting existing book descriptions of how radiation generation and transport takes place in thick plasmas,” Hu states.
” According to our experiments, utilizing a self-consistent DFT technique more accurately explains the transport of radiation in a dense plasma,” states Nilson. “Our technique might supply a reputable method for replicating radiation generation and transportation in thick plasmas encountered in stars and inertial combination targets. The experimental scheme reported here, based on a laser-driven implosion, can be readily extended to a broad range of materials, breaking the ice for significant examinations of severe atomic physics at tremendous pressures.”
Reference: “Probing atomic physics at ultrahigh pressure using laser-driven implosions” by S. X. Hu, David T. Bishel, David A. Chin, Philip M. Nilson, Valentin V. Karasiev, Igor E. Golovkin, Ming Gu, Stephanie B. Hansen, Deyan I. Mihaylov, Nathaniel R. Shaffer, Shuai Zhang and Timothy Walton, 16 November 2022, Nature Communications.DOI: 10.1038/ s41467-022-34618-6.
The research study was funded by the National Nuclear Security Administration, the New York State Energy Research and Development Authority, the National Science Foundation, Sandia National Laboratories, and the University of Rochester..
A new research study from University of Rochester scientists provides speculative information about how radiation takes a trip through dense plasmas, which will help researchers to better comprehend planetary science and blend energy. In a brand-new paper published in the journal Nature Communications, researchers at the University of Rochester Laboratory for Laser Energetics (LLE) used LLEs OMEGA laser to study how radiation takes a trip through thick plasma. X-ray spectroscopy involves intending a beam of radiation in the form of x-rays at a plasma made of atoms– in this case, copper atoms– under severe pressure and heat. The scientists utilized the OMEGA laser both to produce the plasma and to produce the x-rays intended at the plasma.
The scientists experimental measurements show that, when radiation takes a trip through a thick plasma, the changes in atomic energy levels do not follow standard quantum mechanics theories typically utilized in plasma physics models– so-called “continuum-lowering” models.
